1. Field of the Invention
The present invention is related to an alpine ski boot having a rigid shell, provided with an external sole at its base, and in which a portion forming the shell base is overlaid with an upper having a rear portion, or rear spoiler, and a front portion, or front cuff, provided in one or more pieces and journaled with respect to the shell base about at least one transverse journal axis, the shell including an internal sole on its bottom and also receiving internal cushioning in the form of a flexible comfort liner, interposed between the foot and the lower part of the leg, and the rigid shell.
2. Discussion of Background and Material Information
For the above-mentioned type of boot, it is known to provide local reinforcements corresponding to predetermined areas of the foot or of the lower part of the leg so as to modify the rigidity of the boot at right angles with these areas.
For example, in French Patent Publication No. 2,649,594, a boot is known in which an attempt was made to control the forces exerted laterally on the upper, because it was observed that these forces are especially substantial as the skier often takes support on the running edges of the skis.
It is also observed in that French publication, that the manner in which the lateral forces exerted by the leg on the upper of the boot are transmitted to the ski, plays a very important role in the steering of the skis. It is also taught that the collar-shaped uppers of the boots are relatively flexible, and that this flexibility often impedes a precise and instantaneous transmission of the lateral forces from the leg to the ski.
If these observations as well as the problems posed are realistic and concrete, it remains true that the solution proposed, which includes the provision of a side of the upper corresponding to the inner side of the leg with an internal reinforcement, is only a partial solution to the problem.
Indeed, the force thus transmitted by means of the lateral reinforcement of the upper is not directly communicated to the foot, because between the reinforced portion of the upper and the sole of the boot there is an area, in this case consisting of the shell base, that remains relatively flexible. This constitutes an interruption of the progression of the communication, which renders practically useless the presence of the reinforcement in this area.
In addition, if the lateral forces are substantial during skiing, the forces directed in the longitudinal direction of the boot are also substantial when gliding, particularly in the case of forward flexion or rear support, and generate a substantial increase in the vertical pressures on the sole. The above-mentioned solution does not teach anything in this respect.
In French Patent Publication No. 1,395,865 it is also known to reinforce a ski boot by means of a reinforcement element located at the rear level of the heel and extending beneath the latter. This reinforcement also includes two lateral fastening hooks affixed to the upper portion of the boot upper.
This publication does not disclose the modification of the rigidity of the boot in a transverse direction near its sole, which is the seat of all the forces during lateral supports of the ski.
The same is true for the boot described in U.S. Pat. No. 3,618,946, also including a reinforcement at the level of the heel and extended by a sole, without treating the problem of the lateral forces to be transmitted in a positive manner to the ski. In fact, it relates to a soccer shoe that must remain flexible all over in order to allow the foot to flex properly during use of the shoe.
French Patent Publication No. 2,022,109 also describes a ski boot with a reinforced area, but this area only concerns the upper peripheral portion of the upper and does not in any way change the manner of transmitting the lateral forces in the lower portion concerned of the boot.